The present invention relates to fluid driven reciprocating apparatus, particularly to a fluid intensifier, and more particularly to a fluid driven reciprocating apparatus having a double acting power chamber with connected signal rods functioning as high pressure pistons or to transmit reciprocating mechanical power.
In industry, high pressure fluid, which includes air, water, and hydraulic fluid, has many application. For example, delivering fluid at a high pressure is often accomplished with an intensifier, which is a reciprocating fluid device having one or more large pistons connected to one or more small pistons. Intensifiers are powered by a low pressure fluid, such as compressed air or running water. Intensifiers can operate at any flow rate and still maintain their high pressure output, whereas this would be difficult to achieve with a high pressure pump driven by an electric motor, for example.
One common arrangement for an intensifier is one large double-acting low pressure power cylinder containing a piston which has a rod protruding from each face which are each connected to a small piston within a high pressure pumping cylinder. These prior art intensifiers generally have a single 4-way valve which switches both ends of the power chamber between intake and exhaust. The 4-way valve is controlled by one or two small pilot valves which are actuated by the main piston when it reaches either end of its stroke. These prior art intensifiers are relatively complicated.
One example of a market which can benefit from low cost intensifiers are homes having remote water supplies and no cheap source of electricity to pump water to the homes. If, for example, the homes are located on a hill and the water supply is running water in a stream bed at a lower elevation, intensifiers are commonly used to lift the water from the stream bed to a storage tank for the homes. In such instances, the intensifier is located at a lower elevation than the stream bed and is connected via a short pipe having its inlet located in the stream bed (e.g. to provide 10 meters of head water) which can pump water up the hill (e.g. 100 meters above the intensifier). Such commercial intensifiers are known in the art, as exemplified by the High Lifter Water Pump, Real Goods, 1991 Sourcebook, page 219, and U.S. Pat. No. 4,523,895 and U.S. Pat. No. 4,627,794. Other applications for fluid intensifiers include hydraulic and pneumatic applications, as well as for pressure amplifiers and booster pumps.
The present invention involves a fluid intensifier which is of a less complicated structure, and this in view of its simpler construction is lower in cost when compared to the existing commercial units. The present invention is a fluid driven reciprocating apparatus having a single double acting power chamber having a double acting piston which is connected to signal rods which also function as high pressure pistons or to transmit mechanical power. Optionally, only one rod may be used as a pump or power transmitter. When used as an intensifier the signal rods, which each include a pair of spaced seals or sealable members between which is located a vent, in addition to being high pressure pistons, provide a dual use as valve switching mechanisms, thereby replacing the conventionally used pilot valves. The double acting power chamber utilizes two separate intake-exhaust valves controlled by movement of the signal rods. The high pressure section of the apparatus includes two sets of inlet-outlet valves, and by the use of the vents controlled by the signal rods, the driving fluid and driven fluid can't mix.